As integrated circuit devices become more highly integrated, the overall size of metal oxide semiconductor (MOS) transistors have become smaller and channel lengths of the MOS transistors have also been reduced. Accordingly, short channel MOS transistors may experience a punch-through phenomenon that may cause large leakage currents between source and drain regions of the transistor. In addition, source and drain junction capacitances and gate capacitances may also increase. Thus, it may be difficult to provide high performance, low power integrated circuit devices.
To address the problems with MOS transistors discussed above, silicon on insulator (SOI) technology using a SOI substrate has been introduced. A SOI substrate typically includes a supporting substrate, an insulating layer on the supporting substrate and a silicon layer on the insulating layer. SOI devices may provide low junction leakage currents, reduction in frequency of punch-through, low operation voltage and high efficiency in device isolation. However, heat generated from SOI devices during operation may not be efficiently conducted to the supporting substrate due to the insulating layer between the supporting substrate and the silicon layer. Accordingly, temperatures of SOI devices may increase and thereby degrade the overall characteristics of the device. Furthermore, SOI devices may experience a floating body effect that may cause a parasitic bipolar transistor action and complex manufacturing techniques may be used to remove the floating body effect. Accordingly, improved integrated circuit devices and methods of fabricating integrated circuit devices may be desired.